Chapter 10 Boiling and Condensation10-14EWater is boiled at 1 atm pressure and thus at a saturation (or boiling) temperature of Tsat= 212°F by a horizontal polished copper heating element whose surface temperature is maintained at Ts= 788°F. The rate of heat transfer to the water per unit length of the heater is to be determined. Assumptions1 Steady operating conditions exist. 2 Heat losses from the boiler are negligible. PropertiesThe properties of water at the saturation temperature of 212°F are and (Table A-9E). The properties of the vapor at the film temperature of are (Table A-16E) ρl=5982. lbm/ft3hfg=970 Btu / lbmTTTfs=+=+=°()/()/satF22127882500FftBtu/h02267.0FBtu/lbm4707.0ChBtu/lbm0.04564lbm/ft02571.03°⋅⋅=°⋅=⋅==vpvvvkμP = 1 atmWater, 212°F Heating elementAlso, g = 32.2 ft/s2= 32.2×(3600)2ft/h2. Note that we expressed the properties in units that will cancel each other in boiling heat transfer relations. Also note that we used vapor properties at 1 atm pressure from
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.